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Physics · Paper 1 · 2023

29 questions

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Questions (29)

Section A

1. 1 mark

A study that deals with constellation, solar system and cosmos is referred to as

A. Electromagnetism
B. Structure and properties of matter
C. Light
D. Astronomy
E. Geophysics
11. 15 marks

Figure 3 illustrates an electric bell operated by a battery.

(a) The shortest length of the air column in a resonance tube with one end closed and the other end open which resonates to a note of frequency 500 Hz is found to be 160 mm. Calculate the shortest length of the column of air which resonates in similar conditions to a note of frequency 800 Hz. 5 mk
(b) Show how Lenz's law is a special case of the law of conservation of energy. 3 mk
(c(i)) What will happen to the armature A when the switch is closed? 3 mk
(c(ii)) Describe the function of steel strip S. 3 mk

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Section B

3. 6 marks

A camera is used to take a close-up picture of an object. If the object is positioned in front of the lens and a focused image is formed on the film behind the lens, determine the focal length of the camera lens and the height of the image formed on the film.

(3(a)) A convex mirror is often used as the wing mirror of a car instead of plane mirror. Justify this statement giving one point. 3 mk
(a) A convex mirror is often used as the wing mirror of a car instead of plane mirror. Justify this statement giving one point. 3 mk
(b) A camera is used to take a close-up picture of an object 3 cm tall. If the object is positioned 24 cm in front of the lens and a focused image is formed on the film 12 cm behind the lens, determine the focal length of the camera lens and the height of the image formed on the film. 6 mk
(3(b)) A camera is used to take a close-up picture of an object 3 cm tall. If the object is positioned 24 cm in front of the lens and a focused image is formed on the film 12 cm behind the lens, determine the focal length of the camera lens and the height of the image formed on the film. 6 mk

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4. 5 marks

A force of 200 N and 20 cm long spanner and 150 N and 30 cm long spanner were separately used to loosen the left and right front car tire nuts, respectively. Show that the 30 cm long spanner will be more effective than the 20 cm long spanner.

(4(a)) Why is it not be practical to make a barometer with water instead of mercury! 4 mk
(a) Why is it not be practical to make a barometer with water instead of mercury? 4 mk
(b) A force of 200 N and 20 cm long spanner and 150 N and 30 cm long spanner were separately used to loosen the left and right front car tire nuts, respectively. Show that the 30 cm long spanner will be more effective than the 20 cm o spanner. 5 mk
(4(b)) A force of 200 N and 20 cm long spanner and 150 N and 30 cm long spanner were separately used to loosen the left and right front car tire nuts, respectively. Show that the 30 cm long spanner will be more effective than the 20 cm long spanner. 5 mk

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5. 5 marks

Figure 1 shows two simple machines A and B having the same efficiency. Justify that simple machine A requires minimum effort to raise a load of 5000 N.

(5(a)) Why while swimming, the swimmer pushes the water backward with his hands? 4 mk
(a) Why while swimming, the swimmer pushes the water backward with his hands? 4 mk
(b) Figure 1 shows two simple machines A and B having the same efficiency. Justify that simple machine A requires minimum effort to raise a load of 5000 N. 5 mk Diagram for part b
(5(b)) Figure 1 shows two simple machines A and B having the same efficiency. Justify that simple machine A requires minimum effort to raise a load of 5000 N. 5 mk

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6. 4 marks

Figure 2 shows a bimetallic thermostat strip used to regulate the temperature of the room by using a heater and a cooler. Which device between A and B is a heater? Justify your answer.

(6(a)) Figure 2 shows a bimetallic thermostat strip used to regulate the temperature of the room by using a heater and a cooler. Which device between A and B is a heater? Justify your answer. 4 mk
(a) Figure 2 shows a bimetallic thermostat strip used to regulate the temperature of the room by using a heater and a cooler. Which device between A and B is a heater? Justify your answer. 4 mk Diagram for part a

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7. 5 marks

7. (b) With the aid of a diagram, compare the penetrating ability of the three types of radiations on a piece of paper, aluminum sheet and lead block. (5m arks)

(a) Compare the effect of frequency and amplitude to musical sound. Give two points each. 4 mk
(b) With the aid of a diagram, compare the penetrating ability of the three types of radiations on a piece of paper, aluminum sheet and lead block. 5 mk
(a) Compare the effect of frequency and amplitude to musical sound. Give two points each. 4 mk
(b) With the aid of a diagram, compare the penetrating ability of the three types of radiations on a piece of paper, aluminum sheet and lead block. 5 mk

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8. 6 marks

8 (b) Describe the three uses of constellations. (6 marks)

(a) Why are the surface waves more dangerous than the primary and secondary waves? 3 mk
(b) Describe the three uses of constellations. 6 mk
(a) Why are the surface waves more dangerous than the primary and secondary waves? 3 mk
(b) Describe the three uses of constellations. 6 mk

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Section C

9. 3 marks

Why a low voltage supply should have a low internal resistance. Explain by using an appropriate formula. (3 marks)

(c) Why a low voltage supply should have a low internal resistance. Explain by using an appropriate formula. 3 mk
(a) By drawing circuit diagrams supported by the graphs, compare the charging and discharging processes of a capacitor given that you are provided with a cell (E), a voltmeter (V), a switch (S), a capacitor (C), a resistor (R) and connecting wires. 6 mk
(a) By drawing circuit diagrams supported by the graphs, compare the charging and discharging processes of a capacitor given that you are provided with a cell (E), a voltmeter (V), a switch (S), a capacitor (C), a resistor (R) and connecting wires. 6 mk
(b) Two wires A and B of the same material and length have the cross-sectional area in the ratio 2:1. If the same potential difference is applied across each wire, comment on the amount of current flowing between the wires A and B. 6 mk
(c) Why a low voltage supply should have a low internal resistance. Explain by using an appropriate formula. 3 mk
(b) Two wires A and B of the same material and length have the cross-sectional area in the ratio 2:1. If the same potential difference is applied across each wire, comment on the amount of current flowing between the wires A and B. 6 mk

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10. 6 marks

10. (c) Transistor is a three terminal device that is used to amplify the strength of weak signals. Draw the NPN transistor cTCuit connections with four terminals in the following modes: Common Base (C5), Common Emitter (CE) and Common Collector (CC) indicating the input and output circuits. (6 marks)

(a) How will the penetrating power of X rays be affected when their wavelength is reduced? 2 mk
(b) When a speaker is brought near to a Television (TV) operating using cathode ray tube, the picture on the screen is affected but when taken away, the picture becomes normal. Account for this observation. 5 mk
(c) Transistor is a three terminal device that is used to amplify the strength of weak signals. Draw the NPN transistor cTCuit connections with four terminals in the following modes: Common Base (C5), Common Emitter (CE) and Common Collector (CC) indicating the input and output circuits. 6 mk
(b) When a speaker is brought near to a Television (TV) operating using cathode ray tube, the picture on the screen is affected but when taken away, the picture becomes normal. Account for this observation. 5 mk
(c) Transistor is a three terminal device that is used to amplify the strength of weak signals. Draw the NPN transistor circuit connections with four terminals in the following modes: Common Base (C5), Common Emitter (CE) and Common Collector (CC) indicating the input and output circuits. 6 mk
(i) How will the penetrating power of X rays be affected when voltage across X-ray tube is increased? 2 mk
(a) How will the penetrating power of X rays be affected when voltage across X-ray tube is increased? 2 mk

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